The present invention relates to the monitoring of particulate matter in a water supply.
There are numerous objectives for monitoring of sand content in pumped well water. Among the reasons for such monitoring are to ensure the quality of the water supply, to insure the integrity of the well bore to prevent collapse of the well, and to prevent valve wear or damage to pumping installations.
Various devices are known for measuring the sand content in a liquid stream. These devices have the drawbacks of requiring on-site sampling by a technician. Emptying and calibration of such devices are also required.
The present invention seeks to overcome disadvantages of known art by providing an in-line monitoring apparatus, which is entirely automated. This in-line monitoring apparatus monitors the need for quantitative measurement and can be set to repeatedly monitor this need at predetermined intervals. The apparatus can be brought in-line, flushed, activated to perform sand content measurement, and deactivated, entirely by remote control. This ability also provides the possibility to repeat measurements, if necessary or desired.
There is thus provided, in accordance with a preferred embodiment of the present invention, an in-line monitoring apparatus for monitoring particulate matter in a liquid stream, which includes:
an inlet for permitting ingress of a liquid stream into said in-line monitoring apparatus;
an outlet for discharging a liquid stream from said in-line monitoring apparatus;
first and second liquid flow paths each arranged to conduct a liquid flow between said inlet and said outlet;
an in-line particulate matter sampling unit arranged along said first flow path for permitting therein accumulation of particulate matter suspended in a liquid flow between said inlet and outlet, and having apparatus for measuring particulate matter accumulations therein;
apparatus for separating particulate matter from a liquid stream entering said inlet, and for providing the particulate matter to said in-line sampling unit;
first and second valves for selectably permitting liquid flow along said first and second flow paths, respectively, wherein said first valve is arranged downstream of said in-line sampling unit; and
control apparatus for operating said in-line monitoring apparatus in first and second operative modes, wherein, in said first mode, said first valve is closed so as to prevent a through flow of liquid along said first liquid path, and said second valve is open, and in said second mode, said first valve is open so as to permit a through flow of liquid along second liquid path, and said second valve is closed,
wherein, in said first mode, said in-line sampling unit is operative to permit entry and accumulation of particulate matter therein for measurement by said in-line monitoring apparatus, and in said second mode, a flow of liquid along said first conduit passes through said in-line sampling unit so as to remove the particulate matter accumulations therefrom so as to flush out any particulate matter as may have accumulated in said in-line sampling unit.
Further in accordance with a preferred embodiment of the present invention, said in-line sampling unit includes:
at least one sampling chamber for receiving an accumulation of particulate matter; and
at least one apparatus for detecting the presence of at least a predetermined volume of particulate matter in said at least one sampling chamber, said at least one apparatus being operative to provide to said control apparatus an output signal indicative of said at least predetermined volume of particulate matter accumulation,
wherein said in-line monitoring apparatus also includes flow measuring apparatus for measuring the volumetric flow rate of a liquid flowing between said inlet and said outlet operative to provide an output signal to said control apparatus indicative of a rate of liquid flow, and wherein said control apparatus is further operative to evaluate the concentration of particulated matter suspended in the liquid stream per unit flow.
Additionally, in accordance with a preferred embodiment of the present invention, said control apparatus is operable to activate said in-line monitoring apparatus in said first operative mode until detection of said at least predetermined concentration of particulate matter; and wherein, in response to an output signal received from said apparatus for detecting, said control apparatus is operative to switch said in-line monitoring apparatus to said second operative mode.
Preferably, subsequent to said removal of particulate matter from said in-line sampling unit, said control apparatus is operative to switch said in-line monitoring apparatus from said second mode to said first mode.
Alternatively, subsequent to said removal of particulate matter from said in-line sampling unit, said control apparatus is selectably operable to operate said in-line monitoring apparatus in a third mode, during which said apparatus for detecting is inactive for a preselected period of time, after which said control apparatus operates said in-line monitoring apparatus reactivates said apparatus for detecting so as to operate said in-line monitoring apparatus in said first operative mode.
Additionally, in accordance with a preferred embodiment of the present invention, the concentration of particulate matter that said in-line monitoring apparatus is operative to detect is at least approximately 100 ppm.
Further in accordance with a preferred embodiment of the present invention, the concentration of particulate matter that said in-line monitoring apparatus is operative to detect is at least approximately 50 ppm.
Further in accordance with a preferred embodiment of the present invention, the concentration of particulate matter that said in-line monitoring apparatus is operative to detect is at least approximately 1 ppm.
Additionally, in accordance with a preferred embodiment of the present invention, said abovementioned valves are solenoid-type switching valves.
Further in accordance with a preferred embodiment of the present invention, said device for selectively separating a liquid stream from any suspended particulate matter as may be contained therein is a cyclone type device.
Further in accordance with a preferred embodiment of the present invention, said at least one sampling chamber includes a first lower smaller sampling chamber and a second upper larger sampling chamber.
Additionally, in accordance with a preferred embodiment of the present invention, said in-line monitoring apparatus further includes apparatus for inducing settlement of particulate matter from said upper sampling chamber to said lower sampling chamber wherein said upper sampling chamber is formed so as to permit passage of particulate matter to said lower sampling chamber.
Further in accordance with a preferred embodiment of the present invention, apparatus for inducing settlement of particulate matter includes an inclined conduit leading from said upper sampling chamber to said lower sampling chamber.
Additionally, in accordance with a preferred embodiment of the present invention, apparatus for inducing settlement of particulate matter further includes a generally upward conduit leading out from said lower sampling chamber, for allowing a flow of liquid that has entered said lower sampling chamber via said inclined conduit, to exit it.
Further in accordance with a preferred embodiment of the present invention, said apparatus for inducing settlement of particulate matter may include a vibratory unit for vibrating said sampling unit.
Further in accordance with a preferred embodiment of the present invention, said in-line monitoring apparatus includes at least one particulate matter separator arranged along said first flow path, downstream of said in-line sampling unit and upstream of said first valve, for permitting an outflow of particulate matter flushed through said first flow path during activation in said second operative mode, thereby substantially preventing outflow thereof from said outlet.
Further in accordance with a preferred embodiment of the present invention, said in-line monitoring apparatus is arranged so as to tap in to a main-flow conduit such that a stream of liquid entering said in-line monitoring apparatus from the main flow conduit is a substantially representative sample of the liquid flowing through the main flow conduit containing a correspondingly representative volume of suspended particulate matter.
There is thus also provided, in accordance with a preferred embodiment of the present invention, a method of upward flushing of an in-line monitoring apparatus for monitoring particulate matter, which includes:
directing a flow of liquid, generally downward through an inclined conduit, to a sampling chamber, thereby generating turbulence in the sampling chamber; and
flushing the sampling chamber upward, by the turbulent flow, which carries particulate matter upward, through a generally upward conduit.